Race-neutral equations for assessment of lung function in children with thalassemia

The aim of this study was to assess pulmonary dysfunction in children with transfusion-dependent thalassemia (TDT) using the Global Lung Function Initiative (GLI) 2022 race-neutral spirometric reference equations and to determine the main predicting factors. The spirometric results of 68 children with TDT were compared to the results of 68 healthy control subjects using both GLI-2012 reference equations for Caucasians and GLI-2022 global equations. Associations between the spirometric data and various anthropometric, clinical, and laboratory parameters were analyzed to detect predictors of pulmonary dysfunction in this group of patients. Children with TDT showed significantly lower values of FVC and FEV1 with a predominance of the restrictive pattern (23.53%). Thalassemic children with the restrictive pattern were significantly older, had a longer duration of regular blood transfusion, lower height, weight, and BMI z-scores, higher average serum ferritin, and higher frequency of having a serum ferritin level >2500 ng/mL. The strongest predictor for having a restrictive spirometric pattern was high serum ferritin. Our analysis shows that the transition from GLI-2012 spirometric reference equations for Caucasians to the GLI-2022 global equations has led to a reduction in the prevalence rate of restrictive pulmonary dysfunction in children with TDT, which should not affect the patient outcome in the long term. Asymptomatic children with TDT exhibited a restrictive spirometric pattern in a significant proportion. The most important predictor was high serum ferritin. We encourage the inclusion of pulmonary function testing in the routine monitoring of patients with TDT, especially in older patients and those with iron overload.